Electronic stabilization method, image acquisition device, and movable platform

ABSTRACT

The present disclosure provides an image stabilization method. The method includes acquiring a frame of an image to be stabilized and a related exposure time; acquiring first attitude data before the exposure time and second attitude data after the exposure time, wherein the number of the first attitude data is one or more, and the number of the second attitude data is one or more; acquiring a target attitude corresponding to the exposure time based on the first attitude data and the second attitude data; and obtaining a stabilized target image by stabilizing the image to be stabilized according to the target attitude.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of InternationalApplication No. PCT/CN2019/085265, filed on Apr. 30, 2019, the entirecontent of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of control technology, andmore specifically, to an electronic stabilization method, an imageacquisition device, a movable platform, and a machine readable storagemedium.

BACKGROUND

At present, most image acquisition devices, such as motion cameras,implement Electronic Image Stabilization (EIS) algorithms, which may beused to correct the attitude of a video (or an image) acquired by theimage acquisition devices. For example, after a frame of image isexposed, the EIS algorithm may use a low-pass filter to process thespatial attitude data collected by a gyroscope for a period of timebefore the exposure time to generate a smooth curve (e.g., the targetattitude). Subsequently, the EIS algorithm may calculate the amount ofthe attitude compensation based on the target attitude curve, andcorrect the video based on the attitude compensation amount. As such,the user may view a relatively smooth video image.

In the process of generating a smooth curve by using the EIS algorithm,it may be necessary to use a frequency domain low-pass filter. However,the frequency domain low-pass filter may produce a delay in secondsduring the filtering process. If the user rotates the image acquisitiondevice during the delay period, the real-time attitude and the targetattitude of the image acquisition device may be greatly deviated, whichmay result in jittering or twitching of the video image, therebyimpairing the viewing experience.

SUMMARY

The embodiments of the present disclosure provide an electronicstabilization method, an image acquisition device, a movable platform,and a machine readable storage medium.

One aspect of the present disclosure provides an image stabilizationmethod. The method includes acquiring a frame of an image to bestabilized and a related exposure time; acquiring first attitude databefore the exposure time and second attitude data after the exposuretime, wherein the number of the first attitude data is one or more, andthe number of the second attitude data is one or more; acquiring atarget attitude corresponding to the exposure time based on the firstattitude data and the second attitude data; and obtaining a stabilizedtarget image by stabilizing the image to be stabilized according to thetarget attitude.

Another aspect of the present disclosure provides an image acquisitiondevice. The image acquisition device includes: a processor, an imagesensor, and a spatial attitude sensor; and the processor is connected tothe image sensor and the spatial attitude sensor. The processor isconfigured to acquire a frame of an image to be stabilized and itsexposure time; acquire first attitude data before the exposure time andsecond attitude data after the exposure time, wherein the number of thefirst attitude data is one or more, and the number of the secondattitude data is one or more; acquire a target attitude corresponding tothe exposure time based on the first attitude data and the secondattitude data; and obtain a stabilized target image by stabilizing theimage to be stabilized according to the target attitude.

It can be seen from the technical solution described above, in oneembodiment, by acquiring the first attitude data before the exposuretime and the second attitude after the exposure time, the targetattitude corresponding to the exposure time at which the imageacquisition device may be located may be acquired based on the firstattitude data and the second attitude data. Subsequently, the image tobe stabilized may be stabilized based on the target attitude to obtainthe stabilized target image. As such, in the present embodiment, thesecond attitude data may be used to determine the motion of the imageacquisition device after the image to be stabilized is exposed, therebyensuring that a smooth target attitude may be obtained after filteringthe actual motion of the image acquisition device and avoiding jitteringor twitching in the stabilized image, which may improve the stability ofthe display and the viewing experience.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the technical solutions provided in theembodiments of the present disclosure more clearly, the accompanyingdrawings to be used for describing the embodiments are introducedbriefly in the following description. It should be apparent that theaccompanying drawings in the following description are only someembodiments of the present disclosure. Persons of ordinary skill in theart can obtain other accompanying drawings in accordance with theaccompanying drawings without any creative efforts.

FIG. 1 is a flowchart of an electronic stabilization method according toan embodiment of the present disclosure;

FIG. 2 is a flowchart for acquiring a target attitude according to anembodiment of the present disclosure;

FIGS. 3a-3c are schematic diagrams of a real-time attitude and a targetattitude according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a target attitude according to anembodiment of the present disclosure;

FIG. 5 is a flowchart of an electronic stabilization method according toanother embodiment of the present disclosure; and

FIG. 6 is a flowchart of an electronic stabilization method according tostill another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions in the embodiments of the present disclosurewill be described below with reference to the drawings. It will beappreciated that the described embodiments are part rather than all ofthe embodiments of the present disclosure. Other embodiments conceivedby those having ordinary skills in the art on the basis of the describedembodiments without inventive efforts should fall within the scope ofthe present disclosure. In the situation where the technical solutionsdescribed in the embodiments are not conflicting, they can be combined.

At present, most image acquisition devices, such as motion cameras, mayinclude an Electronic Image Stabilization (EIS) algorithm, which may beused to correct the attitude of a video (or an image) acquired by theimage acquisition devices. For example, after a frame of image isexposed, the EIS algorithm may use a low-pass filter to process thespatial attitude data collected by a gyroscope for a period of timebefore the exposure time to generate a smooth curve (e.g., the targetattitude). Subsequently, the EIS algorithm may calculate the amount ofthe attitude compensation based on the target attitude curve, andcorrect the video based on the attitude compensation amount. As such,the user may view a relatively smooth video image.

In the conventional technology, in the process of generating a smoothcurve by using the EIS algorithm, it may be necessary to use a frequencydomain low-pass filter. However, the frequency domain low-pass filtermay produce a delay in seconds during the filtering process. If the userrotates the image acquisition device during the delay period, thereal-time attitude and the target attitude of the image acquisitiondevice may be greatly deviated, which may result in jitters or twitchesof the video image, thereby reducing the viewing experience.

An embodiment of the present disclosure provides an electronicstabilization method. The electronic stabilization method may use theattitude data before and after the exposure time of the image to bestabilized to perform a low-pass filtering on the actual attitude. Assuch, a smoother target attitude may be obtained. Subsequently, theimage to be stabilized may be stabilized based on the target attitude,thereby ensuring the stability of the video image, avoiding thesituation of jittering or twitching, and improving the viewingexperience.

FIG. 1 is a flowchart of an electronic stabilization method according toan embodiment of the present disclosure. The electronic stabilizationmethod may be applied to an image acquisition device, such as a (motion)camera, a video camera, a handheld PTZ platform, etc. The electronicstabilization method is described in more detail below.

Step 101, acquiring a frame of an image to be stabilized and itsexposure time.

In one embodiment, an image sensor in the image acquisition device mayacquire a plurality of original images, which may be the images to bestabilized. The image sensor may be a CCD, a camera, etc. The imagesensor may also acquire a time stamp of the image to be stabilizedduring the process of acquiring each frame of image to be stabilized.For example, the time stamp may be an exposure time of the frame ofimage to be stabilized, or the time stamp may be generated by using apredetermined algorithm based on the exposure time, which is not limitedin the present disclosure. The time stamp in the following embodimentsare described by taking the exposure time as an example.

In one embodiment, a processor in the image acquisition device maycommunicate with the image sensor. As such, the processor may acquirethe image to be stabilized and its exposure time form the image sensor.In one embodiment, a First-In First-Out (FIFO) memory may be arranged inthe image acquisition device, and the processor may store the acquiredimage to be stabilized in the FIFO memory. In other words, after theimage sensor acquired the image to be stabilized, the acquired the imageto be stabilized may be stored in the FIFO memory, then the processormay directly read the image to be stabilized from the FIFO memory.

In one embodiment, before the processor acquires the frame of the imageto be stabilized, a predetermined number of frames of the image to bestabilized acquired by the image sensor may be acquired first, therebyensuring a sufficient delay to facilitate the filtering of the frequencydomain low-pass filter.

The predetermined number of frames of the image to be stabilized may bedetermined in advance. For example, to acquire the an image to bestabilized within 1 second, if the acquisition frequency of the imagesensor is 30 fps, then the predetermined of frames of the image to bestabilized may be 30; and if the acquisition frequency of the imagesensor is 60 fps, then the predetermined of frames of the image to bestabilized may be 60.

In addition, the predetermined number of frames of the image to bestabilized may also be associated based on the frequency domain low-passfilter that may be pre-arranged in the image acquisition device. Forexample, if the frequency domain low-pass filter takes a shorter amountof time to filter the actual attitude of the image acquisition device,the predetermine number of frames of the image to be stabilized may beappropriately increased; and if the frequency domain low-pass filtertakes longer amount of time to filter the actual attitude of the imageacquisition device, the predetermine number of frames of the image to bestabilized may be appropriately reduced.

That is, in the present embodiment, the predetermined number of framesof the image to be stabilized may be adjusted based on the specific usecase. As long as the buffering of the image to be stabilized may berealized, the corresponding solutions may fall within the protectionscope of the present disclosure.

In one embodiment, the frequency domain low-pass filter may include oneor more of the following: a FIR filter, and an IIR filter. It should benoted that a person skilled in the art may select a suitable frequencydomain low-pass filter based on the specific use case. As long as thefrequency domain low-pass filtering may be realized, the correspondingsolutions may fall within the protection scope of the presentdisclosure.

Step 102, acquiring first attitude data before the exposure time andsecond attitude data after the exposure time; the number of the firstattitude data may be one or more, and the number of the second attitudedata may be one or more.

In one embodiment, a spatial attitude sensor in the image acquisitiondevice may periodically acquire the attitude data of the imageacquisition device at different times. The spatial attitude sensor mayinclude a 3-axis gyroscope, a 3-axis accelerometer, a 3-axis electronicfloppy disk, a GPS, etc., and a person skilled in the art may select thespatial attitude sensor based on the specific use case, which is notlimited herein.

The period in which the spatial attitude sensor may acquire the attitudedata may be associated with the period in which the image sensor mayacquire the image to be stabilized. For example, 300 attitude data and30 frames of the image to be stabilized may be acquired in 1 second. Ofcourse, the period in which the spatial attitude sensor may acquire theattitude data may not be associated with the period in which the imagesensor may acquire the image to be stabilized. A person skilled in theart may adjust the association between the period in which the spatialattitude sensor may acquire the attitude data and the period in whichthe image sensor may acquire the image to be stabilized, which is notlimited herein.

In one embodiment, when acquiring the attitude data, the spatialattitude sensor may also generate a time stamp of the attitude data,such as the acquisition time, a stamp generated by using thepredetermined algorithm based on the acquisition time, etc., which isnot limited in the present disclosure.

It may be understood that attitude data corresponding to the time stampof each frame of the image to be stabilized may be included in theattitude data. The correspondence with the time stamp may include thesame time stamp or the difference of the time stamps being less than apredetermined threshold. The threshold may be determined based on thespecific use case, such as 0.01 second, which is not limited herein.

In one embodiment, the processor may acquire the exposure time in step101, and acquire the first attitude data before the exposure time andthe second attitude data after the exposure time based on the exposuretime. Further, the number of the first attitude data may be one or more,and the number of the second attitude data may be one or more. Comparedwith the use of the attitude data before the exposure time (it may beunderstood as the first attitude data of the present disclosure) in theconventional technology, in the embodiments of the present disclosure,the second attitude data may be added on the basis of the first attitudedata to increase the time span of the attitude data, thereby ensuringthat the low frequency motion of the image acquisition device after theexposure time may not affect the target attitude.

In one embodiment, the attitude data may further include third attitudedata corresponding to the exposure time. In this case, the processor maycombine the third attitude data with the first attitude data and thesecond attitude data. In the first attitude data, the third attitudedata may be the last attitude data, and in the second attitude data, thethird attitude data may be the first attitude data. Of course, when thenumber of the first attitude data and the second attitude data arelarge, the attitude data may not be used. A person skilled in the artmay make the adjustment based on the specific use case, which is notlimited herein.

In some embodiments, the first attitude data may correspond to a firsttime period, and the second attitude data may correspond to a secondtime period. The first time period corresponding to the first attitudemay refer to the time difference between the time stamps of the firstattitude data and the last attitude data in the first attitude data. Itshould be noted that if the first attitude data or the second attitudedata only include 1 attitude data, which may correspond to a moment intime, in this case, the moment in time may be replaced by a smallerpredetermined value, such as 0.01 second.

It should be noted that the image stored in the FIFO memory in step 101may correspond to a third time period, and the third time period may beless than the sum of the first time period and the second time period.As such, the first frame or the last frame of the image to be enhancedmay correspond to a sufficient amount of attitude to ensure thesubsequent stabilization effect.

In one embodiment, the range of the values of the first time period andthe second time period may include 0.5 second to 1 second. Consideringthe type of low-pass filter and its operating efficiency, the first timeperiod corresponding to the first attitude data and the second timeperiod corresponding to the second attitude data may be the same, forexample, both may be 0.5 second. In this case, a symmetric frequencydomain low-pass filter may be used to increase the filtering speed.

In another embodiment, the first time period corresponding to the firstattitude data and the second time period corresponding to the secondattitude data may be different, and a symmetric frequency domainlow-pass filter may be used, thereby improving the filtering accuracy.

In one embodiment, considering that each frame of the image to bestabilized may correspond to a set of attitude data (e.g., the firstattitude data and the second attitude data), a storage path of theattitude data may be used as feature data of the frame of the image tobe stabilized while buffering each frame of the image to be stabilized.As such, the processor may read the attitude data from the correspondingstorage path when reading each frame of the image to be stabilized,thereby improving the reading efficiency.

In another embodiment, for two adjacent frames of the image to bestabilized, the second attitude data of the previous frame of the imageto be stabilized and the first attitude data of the subsequent frame ofthe image to be stabilized may not overlap, thereby reducing the amountof data calculation. Or, the previous frame of the image to bestabilized and the first attitude data of the subsequent frame of theimage to be stabilized may overlap, thereby ensuring a smoother targetattitude may be subsequently obtained.

Step 103, acquiring target attitude corresponding to the exposure timeat which the image acquisition device may be located based on the firstattitude data and the second attitude data.

In one embodiment, referring to FIG. 2, the processor may acquire apredetermined frequency domain low-pass filter (correspondingly, step201). The frequency domain low-pass filter may include one or more ofthe following: a FIR filter, and an IIR filter.

Subsequently, the processor may acquire a low frequency signal that maynot exceed a cutoff frequency in the first attitude data and the secondattitude data by inputting the first attitude data and the secondattitude data into the frequency domain low-pass filter and filtering ahigh frequency signal that may exceed the cutoff frequency in the firstattitude data and the second attitude data by using the frequency domainlow-pass filter (correspondingly, step 202). It should be understoodthat if the frequency domain low-pass filter includes the function offrequency domain transformation, then the first attitude data and thesecond attitude data may be directly input to the frequency domainlow-pass filter. Alternatively, if the frequency domain low-pass filterdoes not include the function of frequency domain transformation, then afrequency domain transformation may be performed on the first attitudedata and the second attitude data, and the first and second attitudedata after the frequency domain transformation may be input to thefrequency domain low-pass filter. For the method for performing thefrequency domain transformation, reference may be made to the relatedtechnology, which is not limited herein.

The range of the cutoff frequency of the frequency domain low-passfilter may be between 0.5 Hz and 10 Hz. In one embodiment, the cutofffrequency of the frequency domain low-pass filter may be 0.5 Hz. It maybe understood that the lower the cutoff frequency of the frequencydomain low-pass filter, the stronger the ability to filter the highfrequency signal in the attitude data, and the smoother the targetattitude may be. That is, the slower the motion of the image acquisitiondevice, the lower the impact on the subsequent displayed video image maybe.

Subsequently, the processor may generate the target attitudecorresponding to the exposure time at which the image acquisition devicemay be located based on the low frequency signal in the first attitudedata and the second attitude data that may not exceed the cutofffrequency (correspondingly, step 203).

Taking the monotonic motion of the image acquisition device as anexample, where the monotonic motion may refer to the movement of theimage acquisition device in one direction, including a uniform speed, anacceleration, and a deceleration. Taking the uniform motion as anexample, referring to FIGS. 3a-3c , the actual attitude of the imageacquisition device is illustrated in FIG. 3a , which may include anactual exposure point ET, an exposure time T0, and the attitude dataincluding a first attitude data in a first time period T1 before theexposure time T0, and a second attitude data in a second time period T2after the exposure time T0.

Referring to FIG. 3b , the processor may acquire the first attitudedata, where the time for tasks such as acquiring, storing, andpre-processing may be Delta-t1, the first attitude data may correspondto an actual attitude IT, and a target attitude IE may be obtained basedon the first attitude data. In the case where the frequency domainlow-pass filter may be used as the median filter, a median point EE ofthe first attitude data may be located at T1/2. Since the image to bestabilized at the actual exposure point ET may be stabilized by usingthe data at the median point EE, there may be a delay Delta-t2 betweenthe median point EE and the actual exposure point ET, where the delayDelta-t2 may equal to T1/2. The delay may be due to the processingresult obtained by the low-pass filter, that is, a deviation between themedian point EE and the actual exposure point ET, or it may beunderstood as a filtering error. Further, if the image acquisitiondevice jitters during the delay Delta-t2, a deviation may occur if thedata at the median point EE is used to stabilize the image to bestabilized.

Referring to FIG. 3c , the processor may acquire the first attitude dataand the second attitude data, where the time for tasks such asacquiring, storing, and pre-processing the first attitude data and thesecond attitude data may be Delta-t1, and the first attitude data andthe second attitude data may correspond to an actual attitude IT. TakingT1 equals T2 as an example, the processor may obtain the target attitudeIE based on the first attitude data and the second attitude data. In thecase where the frequency domain low-pass filter may be used as themedian filter, the median point EE of the first attitude data and thesecond attitude data may be located at T0, that is, it may overlap withthe actual exposure point ET. As such, the delay Delta-t2 of T1/2 shownin FIG. 3b may be avoided, that it, the delay Delta-t2 may equal to 0.In this case, when the data at the median point EE is used to stabilizethe image to be stabilized at the actual exposure time ET, the imageacquisition device may not vibrate, such that the result of using thedata at the median point EE to stabilize the image to be stabilized maybe more accuracy.

It should be noted that when the first time period equal to the secondtime period, the median point EE and the actual exposure point ET mayoverlap or be similar, that is, the actual attitude and the targetattitude may overlap. Considering that the processor may need the delayDelta-t1 to acquire and store the attitude data, the fluctuation betweenthe actual attitude and the target attitude may be as shown in FIG. 4.FIG. 4 is a schematic diagram of a target attitude according to anembodiment of the present disclosure. Referring to FIG. 4, a curveindicated by reference numeral 1 may be the actual attitude of the imageacquisition device, and a curve indicated by the reference numeral 2 maybe the target attitude of the image acquisition device. Taking arectangular area 10 and a rectangular area 20 in FIG. 4 as an example. Ajittering portion 11 may be included in the actual attitude 1 in therectangular area 10. After the frequency domain low-pass filtering, anarea 12 corresponding jittering portion 11 on the target attitude may besmoothed. The results corresponding to the reference numerals 21 and 22in the rectangular area 20 may be similar and will not be describedagain.

In one embodiment, when the first time period and the second time periodare different, as the gap between the time period and the second timeperiod increase, the delay between the median point E and the actualexposure point may also increase. It may be understood that with theaddition of the second attitude data in the second time period, thedelay between median point EE and the actual exposure point ET may stillbe less than the delay between the median point EE and the actualexposure point ET shown in FIG. 3b . That is, the IE in FIG. 3c may besmoother than the IE in FIG. 3 b.

It may be understood that in order to increase to efficiency of theelectronic stabilization method, in one embodiment, the delay betweenthe median point EE and the actual exposure point ET may not exceed apredetermined delay threshold. That is, the delay between the zerofrequency of the target attitude and the zero frequency of the actualattitude of the image acquisition device may not exceed thepredetermined delay threshold. In one embodiment, a range of the delaythreshold may be between 0 to 0.5 second. In another embodiment, thedelay threshold may be 0.1 second or 0.5 second.

Step 104, obtaining a stabilized target image by stabilizing the imageto be stabilized by using the target attitude.

In one embodiment, referring to FIG. 5, the processor may segment theimage to be stabilized based on a segmentation method to obtain aplurality of sub-images (correspondingly, step 501). The segmentationmethod may include one or more of the following: a grid segmentation,and a uniform segmentation. Subsequently, the processor may stitch oneor more of the plurality of sub-images based on the target attitudecorresponding to the exposure time of the image to be stabilized toobtain a frame of stitched image; and the stitched image may be thestabilized target image (correspondingly, step 502).

It may be understood that the size of the target image may be smallerthan the size of the image to be stabilized. In other words, the targetimage may be a portion of the image may be a portion of the image thatmay be cropped from the image to be stabilized.

It should be noted that during the stitching process, the targetattitude may be close to the edge of the image to be stabilized, in thiscase, the target attitude may need to be properly translated, therebyensuring that the target image may not include an edge region of theimage to be stabilized or a blank region outside the image.

In one embodiment, the processor may directly stabilize the image to bestabilized based on the target attitude corresponding to the exposuretime of each of the images to be stabilized, and the stabilizationmethod may be referred to the stabilization method shown in FIG. 5.

In one embodiment, the processor may acquire a previous frame of thetarget image. Further, the processor may directly stabilize each of theimages to be stabilized in response to the target image not exceeding aboundary of the image to be stabilized; and the processor may stabilizeeach of the images to be stabilized in a case where the processor maymaintain a boundary of the target image not exceeding the boundary ofimage to be stabilized in response to the boundary of the target imagecoinciding with the boundary of the image to be stabilized.

It may be understood that in the present embodiment, only two examplesof the image stabilization method were introduced. A person skilled inthe art may select an appropriate image stabilization method based onthe specific use case, and the corresponding solution may fall withinthe protection scope of the present disclosure.

Referring to FIG. 6, after the processor sequentially stabilizes eachframe of the image to be stabilized, an input video may be realized. Assuch, after the video is outputted and displayed, a relatively stableimage may be displayed.

It can be seen that by acquiring the first attitude data before theexposure time and the second attitude after the exposure time, thetarget attitude corresponding to the exposure time at which the imageacquisition device may be located may be acquired based on the firstattitude data and the second attitude data. Subsequently, the image tobe stabilized may be stabilized based on the target attitude to obtainthe stabilized target image. As such, in the present embodiment, thesecond attitude data may be used to determine the motion of the imageacquisition device after the image to be stabilized is exposed, therebyensuring that a smooth target attitude may be obtained after filteringthe actual motion of the image acquisition device and avoiding jitter ortwitching in the stabilized image, which may improve the stability ofthe display and the viewing experience.

In one embodiment, the present disclosure further provides an imageacquisition device. The image acquisition device may include aprocessor, an image sensor, and a spatial attitude sensor. The processormay be communicatively connected with the image sensor and the spatialattitude sensor. The process may be configured to acquire a frame of animage to be stabilized and its exposure time; acquire first attitudedata before the exposure time and second attitude data after theexposure time, where the number of the first attitude data may be one ormore, and the number of the second attitude data may be one or more;acquire a target attitude corresponding to the exposure time at whichthe image acquisition device may be located based on the first attitudedata and the second attitude data; and obtain a stabilized target imageby stabilizing the image to be stabilized by using the target attitude.

In one embodiment, before acquiring a frame of the image to bestabilized, the processor may be further configured to acquire apredetermined number of frames of the image to be stabilized acquired bythe image sensor in the image acquisition device, wherein the image tobe stabilized may include a time stamp.

In one embodiment, the image to be stabilized may be stored in a FIFOmemory which may be used to store a predetermined number of frames ofimage.

In one embodiment, before acquiring a frame of the image to bestabilized, the processor may be further configured to acquire theattitude data acquired by the spatial attitude sensor in the imageacquisition device. The attitude data may include the first attitudedata, the second attitude data, and the third attitude data of theexposure time; a time stamp; and attitude data that may correspond tothe time stamp of each image to be stabilized.

In one embodiment, the first time period corresponding to the firstattitude data and the second time period corresponding to the secondattitude data may be the same; or, the first time period correspondingto the first attitude data and the second time period corresponding tothe second attitude data may be different.

In one embodiment, the range of the values of the first time period andthe second time period may include 0.5 second to 1 second.

In one embodiment, for two adjacent frames of image to be stabilized,the second attitude data of the previous frame of the image to bestabilized and the first attitude data of the subsequent frame of theimage to be stabilized may overlap.

In one embodiment, the image to be stabilized of the image stored in theFIFO memory may correspond to the third time period, and the third timeperiod may be less than the sum of the first time period and the secondtime period.

In one embodiment, the processor may be configured to acquire a targetattitude corresponding to the exposure time at which the imageacquisition device may be located based on the first attitude data andthe second attitude data, which may include acquiring a predeterminedfrequency domain low-pass filter; acquire a low frequency signal thatmay not exceed a cutoff frequency in the first attitude data and thesecond attitude data by inputting the first attitude data and the secondattitude data into the frequency domain low-pass filter and filtering ahigh frequency signal that may exceed the cutoff frequency in the firstattitude data and the second attitude data by using the frequency domainlow-pass filter; and generate the target attitude corresponding to theexposure time at which the image acquisition device may be located basedon the low frequency signal in the first attitude data and the secondattitude data that may not exceed the cutoff frequency.

In one embodiment, the delay between the zero frequency of the targetattitude and the zero frequency of the actual attitude of the imageacquisition device may not exceed the predetermined delay threshold.

In one embodiment, a range of the delay threshold may be between 0 to0.5 second.

In one embodiment, the range of the cutoff frequency of the frequencydomain low-pass filter may be between 0.5 Hz and 10 Hz.

In one embodiment, the frequency domain low-pass filter may include oneor more of the following: a FIR filter, and an IIR filter.

In one embodiment, the processor may be configure to obtain a stabilizedtarget image based on the image to be stabilized by using the targetattitude, which may include segmenting the image to be stabilized basedon a segmentation method to obtain a plurality of sub-images; andstitching one or more of the plurality of sub-images based on the targetattitude corresponding to the exposure time of the image to bestabilized to obtain a frame of stitched image, where the stitched imagemay be the stabilized target image.

In one embodiment, the present disclosure further provides a movableplatform. The movable platform may include a body, a power supplybattery, a power system, a flight controller, and an image acquisitiondevice as described in the above embodiments. The power supply batterymay be used to power the power system, and the power system may providethe flight power to an unmanned aerial vehicle.

In one embodiment, the present disclosure further provides amachine-readable storage medium. The machine-readable storage medium maystore a plurality of computer executable instructions that, whenexecuted, may implement the processes of the method shown in FIGS. 1-5.

It should be noted that the relationship terms used in the text of thisapplication, such as first and second, are only for distinguishing anobject or operation from another object or operation, but not fordefining or implying any practical relation or order between the objector operation. The terms “include”, “contain” or other alternatives shallbe non-exclusiveness, the inclusion of a series of element such asprocess, method, object or equipment shall include not only the alreadymentioned elements but also those elements not mentioned, and shallinclude the elements which are inherent in the process, method, objector equipment. However, under the condition of no more limitations, thedefinition of an essential element limited by the sentence “including a. . . ” shall not obviate that in addition to containing the saidessential element in the process, method, object or equipment, otheressential element of the same nature may also exist in theabove-mentioned process, method, object or equipment.

The electronic stabilization method, image acquisition device, movableplatform, and the machine-readable storage medium provided inembodiments of the present disclosure have been described in detailabove, in the present disclosure the particular examples are used toexplain the principle and embodiments of the present disclosure, and theabove description of embodiments is merely intended to facilitateunderstanding the methods in the embodiments of the disclosure andconcept thereof; meanwhile, it is apparent to persons skilled in the artthat changes can be made to the particular implementation andapplication scope of the present disclosure based on the concept of theembodiments of the disclosure, in view of the above, the contents of thespecification shall not be considered as a limitation to the presentdisclosure.

1. An electronic stabilization method, comprising: acquiring, by animage acquisition device, a frame of an image to be stabilized and arelated exposure time and storing the image to be stabilized; acquiringfirst attitude data before the exposure time and second attitude dataafter the exposure time, wherein the number of the first attitude datais one or more, and the number of the second attitude data is one ormore; acquiring a target attitude corresponding to the exposure timebased on the first attitude data and the second attitude data; andobtaining a stabilized target image by stabilizing the stored image tobe stabilized according to the target attitude.
 2. The method of claim1, wherein before acquiring the frame of the image to be stabilized, themethod further includes: acquiring a number of the frames of the imageto be stabilized acquired by an image sensor of the image acquisitiondevice, the image to be stabilized including a time stamp, and storingthe number of frames of the image to be stabilized.
 3. The method ofclaim 1, wherein storing the image to be stabilized comprises storingthe image to be stabilized in a first-in first-out memory.
 4. The methodof claim 2, wherein before acquiring the frame of the image to bestabilized, the method further includes: acquiring attitude dataobtained by a spatial attitude sensor of the image acquisition device,the attitude data including: the first attitude data and the secondattitude data, or a third attitude data of the exposure time; the timestamp; and one attitude data that corresponds to the time stamp of eachimage to be stabilized.
 5. The method of claim 1, wherein a first timeperiod corresponding to the first attitude data and a second time periodcorresponding to the second attitude data are different.
 6. The methodof claim 5, wherein a value range of the first time period and thesecond time period includes 0.5 second to 1 second.
 7. The method ofclaim 5, wherein for two adjacent frames of stored images to bestabilized, the second attitude data of a previous frame of the image tobe stabilized overlaps with the first attitude data of a subsequentframe of the image to be stabilized.
 8. The method of claim 5, whereinthe image to be stabilized corresponds to a third time period, the thirdtime period being less than a sum of the first time period and thesecond time period.
 9. The method of claim 1, further including:acquiring a frequency domain low-pass filter; acquiring a low frequencysignal that does not exceed a cutoff frequency in the first attitudedata and the second attitude data by filtering a high frequency signalthat exceeds the cutoff frequency in the first attitude data and thesecond attitude data using the frequency domain low-pass filter; andgenerating the target attitude corresponding to the exposure time basedon the low frequency signal in the first attitude data and the secondattitude data that does not exceed the cutoff frequency.
 10. The methodof claim 9, wherein a delay between the exposure time of the targetattitude and an exposure time of an actual attitude of the imageacquisition device does not exceed a delay threshold.
 11. The method ofclaim 10, wherein a value range of the delay threshold includes 0-0.5seconds.
 12. The method of claim 9, wherein a value range of the cutofffrequency of the frequency domain low-pass filter is between 0.5 Hz to10 Hz.
 13. The method of claim 9, wherein the frequency domain low-passfilter includes one or more of a FIR filter and an IIR filter.
 14. Themethod of claim 1, further including: segmenting the image to bestabilized based on a segmentation method to obtain a plurality ofsub-images; and stitching one or more of the plurality of sub-imagesbased on the target attitude corresponding to the exposure time of theimage to be stabilized to obtain a frame of stitched image, wherein thestitched image is the stabilized target image.
 15. An image acquisitiondevice comprising: a processor, an image sensor, and a spatial attitudesensor; wherein the processor is connected to the image sensor and thespatial attitude sensor; and wherein the processor is configured to:acquire a frame of an image to be stabilized and an exposure time of theimage to be stabilized and store the image to be stabilized; acquirefirst attitude data before the exposure time and second attitude dataafter the exposure time, wherein the number of the first attitude datais one or more, and the number of the second attitude data is one ormore; acquire a frequency domain low-pass filter; acquire a lowfrequency signal that does not exceed a cutoff frequency in the firstattitude data and the second attitude data by filtering a high frequencysignal that exceeds the cutoff frequency in the first attitude data andthe second attitude data using the frequency domain low-pass filter;generate a target attitude corresponding to the exposure time at whichthe image acquisition device is located based on the low frequencysignal in the first attitude data and the second attitude data that doesnot exceed the cutoff frequency; and obtain a stabilized target image bystabilizing the stored image to be stabilized according to the targetattitude.
 16. The image acquisition device of claim 15, wherein theprocessor is further configured to: acquire a number of the frames ofthe image to be stabilized acquired by the image sensor in the imageacquisition device, the image to be stabilized including a time stamp,and store the number of frames of the image to be stabilized.
 17. Theimage acquisition device of claim 15, wherein a first time periodcorresponding to the first attitude data and a second time periodcorresponding to the second attitude data are the same.
 18. (canceled)19. The image acquisition device of claim 15 wherein a delay between theexposure time of the target attitude and an exposure time of an actualattitude of the image acquisition device does not exceed a delaythreshold.
 20. The image acquisition device of claim 15, wherein theprocessor is further configured to: segment the image to be stabilizedbased on a segmentation method to obtain a plurality of sub-images; andstitch one or more of the plurality of sub-images based on the targetattitude corresponding to the exposure time of the image to bestabilized to obtain a frame of stitched image, the stitched image beingthe stabilized target image.
 21. The image acquisition device of claim15, wherein the processor is further configured to store the image to bestabilized in a first-in first-out memory.